include/linux/ceph/pagelist.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __FS_CEPH_PAGELIST_H
   3 #define __FS_CEPH_PAGELIST_H
   4
   5 #include <asm/byteorder.h>
   6 #include <linux/refcount.h>
   7 #include <linux/list.h>
   8 #include <linux/types.h>
   9
  10 struct ceph_pagelist {
  11         struct list_head head;
  12         void *mapped_tail;
  13         size_t length;
  14         size_t room;
  15         struct list_head free_list;
  16         size_t num_pages_free;
  17         refcount_t refcnt;
  18 };
  19
  20 struct ceph_pagelist_cursor {
  21         struct ceph_pagelist *pl;   /* pagelist, for error checking */
  22         struct list_head *page_lru; /* page in list */
  23         size_t room;                /* room remaining to reset to */
  24 };
  25
  26 static inline void ceph_pagelist_init(struct ceph_pagelist *pl)
  27 {
  28         INIT_LIST_HEAD(&pl->head);
  29         pl->mapped_tail = NULL;
  30         pl->length = 0;
  31         pl->room = 0;
  32         INIT_LIST_HEAD(&pl->free_list);
  33         pl->num_pages_free = 0;
  34         refcount_set(&pl->refcnt, 1);
  35 }
  36
  37 extern void ceph_pagelist_release(struct ceph_pagelist *pl);
  38
  39 extern int ceph_pagelist_append(struct ceph_pagelist *pl, const void *d, size_t l);
  40
  41 extern int ceph_pagelist_reserve(struct ceph_pagelist *pl, size_t space);
  42
  43 extern int ceph_pagelist_free_reserve(struct ceph_pagelist *pl);
  44
  45 extern void ceph_pagelist_set_cursor(struct ceph_pagelist *pl,
  46                                      struct ceph_pagelist_cursor *c);
  47
  48 extern int ceph_pagelist_truncate(struct ceph_pagelist *pl,
  49                                   struct ceph_pagelist_cursor *c);
  50
  51 static inline int ceph_pagelist_encode_64(struct ceph_pagelist *pl, u64 v)
  52 {
  53         __le64 ev = cpu_to_le64(v);
  54         return ceph_pagelist_append(pl, &ev, sizeof(ev));
  55 }
  56 static inline int ceph_pagelist_encode_32(struct ceph_pagelist *pl, u32 v)
  57 {
  58         __le32 ev = cpu_to_le32(v);
  59         return ceph_pagelist_append(pl, &ev, sizeof(ev));
  60 }
  61 static inline int ceph_pagelist_encode_16(struct ceph_pagelist *pl, u16 v)
  62 {
  63         __le16 ev = cpu_to_le16(v);
  64         return ceph_pagelist_append(pl, &ev, sizeof(ev));
  65 }
  66 static inline int ceph_pagelist_encode_8(struct ceph_pagelist *pl, u8 v)
  67 {
  68         return ceph_pagelist_append(pl, &v, 1);
  69 }
  70 static inline int ceph_pagelist_encode_string(struct ceph_pagelist *pl,
  71                                               char *s, size_t len)
  72 {
  73         int ret = ceph_pagelist_encode_32(pl, len);
  74         if (ret)
  75                 return ret;
  76         if (len)
  77                 return ceph_pagelist_append(pl, s, len);
  78         return 0;
  79 }
  80
  81 #endif